How deep do marine mammals dive?

The maximum depths and the longest durations of time underwater by various aquatic mammals are listed below:

Mammal	Maximum Depth (feet/meters)	Maximum Time Underwater
Porpoise	984 / 300	15 minutes
Fin whale	1,148 / 350	20 minutes
Bottle-nosed whale	1,476 / 450	120 minutes
Weddell seal	1,968 / 600	70 minutes
Sperm whale	> 6,562 / > 2,000	90 minutes